Armored Skaab

When Armored Skaab enters, mill four cards.

Tome Scour

Search your library for a card, put that card into your hand, then shuffle.

Defender
Whenever you cast an instant or sorcery spell, you may draw a card. If you do, discard a card. This ability triggers only once each turn.

Target player mills three cards.
Flashback {1}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

If you would draw a card while your library has no cards in it, you win the game instead.

Target player mills two cards.
Draw a card.

Counter target spell. Untap up to four lands.

Drowned Catacomb enters tapped unless you control an Island or a Swamp.
{T}: Add {U} or {B}.

Halimar Depths enters tapped.
When Halimar Depths enters, look at the top three cards of your library, then put them back in any order.
{T}: Add {U}.

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.

Delirium — This spell costs {2} less to cast if there are four or more card types among cards in your graveyard.
Draw three cards.

Return up to two target creature cards from your graveyard to your hand.

Draw a card.
Flashback {2}{U} (You may cast this card from your graveyard for its flashback cost. Then exile it.)